By then you can get a MB + 2GHz CPU for about $200;
a big hard disk (~60GB) for about $100;
a faster CD-RW (~32X) for less than $100);
a sounblaster live OEM for around $30 (but you don't need to if you're soundcard is ok or you have a decent on-board sound)
If you're not a gamer, then your video card is fine.
However, the memory might not be able to run at 133MHz. In that case, you should upgrade MB, CPU and memory for around $300. You should buy DDR memory since it's faster than SDRAM. Then wait for good deals on HDD and CD-RW later.